In manufacturing of a semiconductor device, there is known a chemical mechanical polishing (CMP) apparatus that polishes the surface of a substrate. A substrate processing system including the CMP apparatus includes a polishing unit (a CMP unit) for performing polishing of the substrate, a cleaning unit for performing cleaning and drying of the substrate, and a load/unload unit that passes the substrate to the polishing unit and receives the substrate cleaned and dried by the cleaning unit. In the polishing unit, a polishing pad is stuck on the upper surface of a polishing table and a polishing surface is formed. The polishing unit presses a surface to be polished to the substrate, which is held by a top ring, against the polishing surface and rotates the polishing table and the top ring while supplying slurry serving as polishing liquid to the polishing surface. Consequently, the polishing surface and the surface to be polished are relatively moved in a sliding manner and the surface to be polished is polished. Further, in a patent application of the applicant, a finishing unit that presses a contact member having a diameter smaller than the diameter of the substrate against the substrate after the polishing and relatively moves the substrate is provided in the CMP apparatus separately from a main polishing section to slightly additionally polish the substrate and clean the substrate.